1. Technical Field
The invention relates generally to semiconductor device structures and more specifically to a gas dielectric with support structure formed on a semiconductor device structure.
2. Related Art
In order to enhance chip operational speed, semiconductor devices have been continuously scaled down in size. Unfortunately, as semiconductor device size is decreased, the capacitive coupling between conductors in a circuit tends to increase since the capacitive coupling is inversely proportional to the distance between the conductors. This coupling may ultimately limit the speed of the chip or otherwise inhibit proper chip operation if steps are not taken to reduce the coupling.
The capacitance between conductors is also dependent on the insulator, or dielectric, used to separate the conductors. Traditional semiconductor fabrication commonly employs silicon dioxide as a dielectric, which has a dielectric constant of approximately 3.9. One challenge facing further development is finding materials with a lower dielectric constant that can be used between the conductors. As the dielectric constant of such materials is decreased, the speed of performance of the chip is increased. Some materials that have been used to provide a lower dielectric constant between conductors include fluorinated glass, organic materials and organic materials containing gas, such as air. Unfortunately, organic materials suffer from temperature limitations, shrinkage or swelling during manufacturing or chip operation, and poor structural integrity. Application of simple gas dielectric structures tends to create sagging of long line conductors as well as producing poor structural integrity.
Accordingly, a need has developed in the art for a method of forming a dielectric structure on a semiconductor device structure that will provide low capacitance but adequate support for the conductors.